forgetest1
/
antlr
forked from jasder/antlr
1
0
Fork 0
Code Issues Pull Requests 1 Releases Wiki Activity

fixed hideous bug found by sam in getAmbigAlts 

[git-p4: depot-paths = "//depot/code/antlr4/main/": change = 9525]
This commit is contained in:
parrt 2011-12-04 18:21:24 -08:00
parent 110fafde5a
commit b09077209c
2 changed files with 106 additions and 58 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

162
runtime/Java/src/org/antlr/v4/runtime/atn/ParserATNSimulator.java
View File

@ -867,52 +867,100 @@ public class ParserATNSimulator<Symbol> extends ATNSimulator {
if ( c.state.getClass() == RuleStopState.class ) {
return c;
}
}
}
return null;
}
}
}
return null;
}
/**
* From grammar:
s' : s s ;
s : x? | x ;
x : 'a' ;
config list: (4,1), (11,1,4), (7,1), (3,1,1), (4,1,1), (8,1,1), (7,1,1), (8,2), (11,2,8), (11,1,[8 1])
state to config list:
3 -> (3,1,1)
4 -> (4,1), (4,1,1)
7 -> (7,1), (7,1,1)
8 -> (8,1,1), (8,2)
11 -> (11,1,4), (11,2,8), (11,1,8 1)
Walk and find state config lists with > 1 alt. If none, no conflict. return null. Here, states 11
and 8 have lists with both alts 1 and 2. Must check these config lists for conflicting configs.
*/
@Nullable
public Set<Integer> getAmbiguousAlts(@NotNull OrderedHashSet<ATNConfig> configs) {
// System.out.println("### check ambiguous "+configs);
Set<Integer> ambigAlts = null;
// First get a list of configurations for each state.
// Most of the time, each state will have one associated configuration.
MultiMap<Integer, ATNConfig> stateToConfigListMap = new MultiMap<Integer, ATNConfig>();
for (ATNConfig c : configs) {
stateToConfigListMap.map(c.state.stateNumber, c);
}
// potential conflicts are states, s, with > 1 configurations and diff alts
// find all alts with potential conflicts
int numPotentialConflicts = 0;
for (int state : stateToConfigListMap.keySet()) { // for each state
List<ATNConfig> configsPerState = stateToConfigListMap.get(state);
ATNConfig goal = configsPerState.get(0);
int goalAlt = goal.alt;
boolean thisStateHasMultipleAlts = false;
for (ATNConfig c : configsPerState) { // look for diff alt in state's config list
if ( c.alt!=goalAlt ) {
numPotentialConflicts++;
thisStateHasMultipleAlts = true; // found diff alt
break;
}
}
if ( !thisStateHasMultipleAlts ) {
// remove state's configurations from further checking; no issues with them.
// (can't remove as it's concurrent modification; set to null)
stateToConfigListMap.put(state, null);
}
}
// System.out.println("### stateToConfigListMap="+stateToConfigListMap);
if ( numPotentialConflicts==0 ) return null;
// compare each pair of configs in sets for states with > 1 alt in config list, looking for
// (s, i, ctx) and (s, j, ctx') where ctx==ctx' or one is suffix of the other.
for (List<ATNConfig> configsPerState : stateToConfigListMap.values()) {
if (configsPerState == null) continue;
int size = configsPerState.size();
for (int i = 0; i < size; i++) {
ATNConfig c = configsPerState.get(i);
for (int j = i+1; j < size; j++) {
ATNConfig d = configsPerState.get(j);
boolean sameCtx =
(c.context==null&&d.context==null) ||
c.context.equals(d.context) ||
c.context.conflictsWith(d.context);
// System.out.println("compare "+c+" to "+d+", same="+sameCtx);
if ( sameCtx ) {
if ( debug ) {
System.out.println("we reach state "+c.state.stateNumber+
" in rule "+
(parser !=null ? getRuleName(c.state.ruleIndex) :"n/a")+
" alts "+c.alt+","+d.alt+" from ctx "+c.context.toString(parser)
+" and "+ d.context.toString(parser));
}
if ( ambigAlts==null ) ambigAlts = new HashSet<Integer>();
ambigAlts.add(c.alt);
ambigAlts.add(d.alt);
}
}
}
}
// System.out.println("### ambigAlts="+ambigAlts);
@Nullable
public Set<Integer> getAmbiguousAlts(@NotNull OrderedHashSet<ATNConfig> configs) {
// System.err.println("check ambiguous "+configs);
Set<Integer> ambigAlts = null;
// First get a list of configurations for each state.
// Most of the time, each state will have one associated configuration.
MultiMap<Integer, ATNConfig> stateToConfigListMap =
new MultiMap<Integer, ATNConfig>();
for (ATNConfig c : configs) {
stateToConfigListMap.map(c.state.stateNumber, c);
}
// potential conflicts are states with > 1 configuration and diff alts
for (List<ATNConfig> configsPerState : stateToConfigListMap.values()) {
ATNConfig goal = configsPerState.get(0);
int size = configsPerState.size();
for (int i=1; i< size; i++) {
ATNConfig c = configsPerState.get(i);
if ( c.alt!=goal.alt ) {
//System.out.println("chk stack "+goal+", "+c);
boolean sameCtx =
(goal.context==null&&c.context==null) ||
goal.context.equals(c.context) ||
c.context.conflictsWith(goal.context);
if ( sameCtx ) {
if ( debug ) {
System.out.println("we reach state "+c.state.stateNumber+
" in rule "+
(parser !=null ? getRuleName(c.state.ruleIndex) :"n/a")+
" alts "+goal.alt+","+c.alt+" from ctx "+goal.context.toString(parser)
+" and "+ c.context.toString(parser));
}
if ( ambigAlts==null ) ambigAlts = new HashSet<Integer>();
ambigAlts.add(goal.alt);
ambigAlts.add(c.alt);
}
}
}
}
if ( ambigAlts!=null ) {
//System.err.println("ambig upon "+input.toString(startIndex, input.index()));
}
return ambigAlts;
}
@ -1076,17 +1124,19 @@ public class ParserATNSimulator<Symbol> extends ATNSimulator {
public void dumpDeadEndConfigs(@NotNull NoViableAltException nvae) {
System.err.println("dead end configs: ");
for (ATNConfig c : nvae.deadEndConfigs) {
Transition t = c.state.transition(0);
String trans = "";
if ( t instanceof AtomTransition) {
AtomTransition at = (AtomTransition)t;
trans = "Atom "+getTokenName(at.label);
}
else if ( t instanceof SetTransition ) {
SetTransition st = (SetTransition)t;
boolean not = st instanceof NotSetTransition;
trans = (not?"~":"")+"Set "+st.set.toString();
}
String trans = "no edges";
if ( c.state.getNumberOfTransitions()>0 ) {
Transition t = c.state.transition(0);
if ( t instanceof AtomTransition) {
AtomTransition at = (AtomTransition)t;
trans = "Atom "+getTokenName(at.label);
}
else if ( t instanceof SetTransition ) {
SetTransition st = (SetTransition)t;
boolean not = st instanceof NotSetTransition;
trans = (not?"~":"")+"Set "+st.set.toString();
}
}
System.err.println(c.toString(parser, true)+":"+trans);
}
}

2
tool/test/org/antlr/v4/test/TestSemPredEvalParser.java
View File

@ -248,8 +248,6 @@ public class TestSemPredEvalParser extends BaseTest {
assertEquals(expecting, result);
}
// TODO: test predicates that are validating predicates; not ambiguous decisions
@Test public void testToLeft() throws Exception {
String grammar =
"grammar T;\n" +